JPH03256049A - Method and device for drying resist coating film - Google Patents

Abstract

PURPOSE:To allow the correction of a drying point in real time by determining the drying point where drying is completed from the distribution of the moisture contents of the resist coating films detected at different plural points in the progressing direction of a metallic thin film and controlling drying conditions during drying in such a manner that the drying point is positioned in a prescribed point. CONSTITUTION:The continuous thin metallic sheet 1 continuously passes a coating tank 2 and the resist coating films are formed on both surfaces thereof. This sheet continuously enters the drying furnace 3 where the sheet is dried. The moisture contents of the resist coating films are detected at the plural different points in the progressing direction of the metallic thin film 1 and the drying point where the drying is completed is determined from the distribution of the detected moisture contents. The drying conditions in the drying furnace 3 are then so controlled that the drying point exists in the prescribed position. The need for relying on visual observation to confirm the drying point is eliminated in this way and the drying point is stably set without manual labor. The correction of the drying in real time is thus executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing thin metal plate products with patterns formed by chemical etching, such as shadow masks and lead frames, and in particular, a method for drying a resist coating film. and a device therefor.

[Conventional technology]

When molding thin metal products such as shadow masks and lead frames, the resist pattern that serves as a mask for selective chemical etching is created by applying a resist film to the thin metal plate, thoroughly drying it, and then exposing it to light, developing it, and hardening it. It is formed by applying film processing, burning processing, etc. Among these, properly drying the resist coating film is important for improving the quality of the final product. Conventionally, the drying atmosphere temperature was set according to the resist film thickness based on the empirical rules of experienced people, and then the drying point, which is the point at which drying was completed, was confirmed by visually checking the drying line, and drying was performed based on the results. Fine adjustments were made to the conditions to stabilize the drying point.

[Problem to be solved by the invention]

However, the conventional method described above relies on the human eye to detect dry points, which has the disadvantage that the detection results vary and become uncertain. In addition, since humans measure at regular intervals, there is the problem that drying conditions (drying points) cannot be corrected in real time, and in extreme cases, the resist coating film may come out of the drying process without being dried. There was also. If the drying point is unstable, the sensitivity of the dried resist film will become unstable, so the final product manufactured from the resist film that has undergone the visually monitored drying process as described above
It was not necessarily stable and highly uniform.

The present invention was made in view of this situation, and
The purpose of this is to solve the above-mentioned problems with the conventional method of drying resist coatings, and to be able to stably set the drying point without relying on visual measurements or relying on human hands to confirm the drying point. It is an object of the present invention to provide a method and apparatus for drying a resist coating film, which allows drying points to be corrected in real time.

[Means to solve the problem]

The method for drying a resist coating film of the present invention is a method for drying a resist coating film in the manufacturing process of a thin metal sheet product in which a pattern is formed on a thin metal plate by chemical etching, and the drying method is a method for drying a resist coating film in a manufacturing process of a thin metal sheet product in which a pattern is formed on a thin metal plate by chemical etching. In a drying method in which the resist coating film is dried by passing it through a drying oven that can set drying conditions in different directions, the moisture content of the resist coating film is detected at a plurality of points in different directions, and the drying process is determined based on the distribution of the detected moisture content. The method is characterized in that a drying point, which is a completed point, is determined, and the drying conditions in the drying oven are adjusted so that the drying point is located at a predetermined position.

In this case, if the drying conditions are adjusted by adjusting the drying conditions in the latter half of the drying oven in the direction in which the thin metal plate advances, the thickness of the coating film will not change due to dripping, and the desired adjustment will be achieved. can do. Further, if the drying conditions are adjusted in real time, the drying point becomes more stable and the sensitivity of the resist film becomes more stable.

The resist coating film drying device of the present invention is used in the resist coating film drying device in the manufacturing process of metal thin sheet products in which a pattern is formed on a metal thin plate by chemical etching. A drying oven that allows the thin metal plate to pass through and dry, the drying oven having a drying condition setting means that can set different drying conditions in the direction in which the thin metal plate moves, and a plurality of points in the drying oven that are different in the direction in which the thin metal plate moves. means for detecting the moisture content of the resist coating film at the plurality of different points; means for determining the position of a drying point, which is the point at which drying is completed, from the moisture content detected at the plurality of different points; and a method for setting the determined drying point position. The apparatus is characterized by comprising means for determining the amount of deviation from the point position, and adjusting means for changing the output of the drying condition setting means in accordance with the determined amount of deviation.

[Effect]

According to the resist coating film drying method and apparatus of the present invention,
The moisture content of the resist coating film is detected at multiple points in different directions of the metal thin film, and the drying point, which is the point at which drying is completed, is determined from the distribution of the detected moisture content, and the drying point is located at a predetermined position. Since the drying conditions in the drying oven are adjusted accordingly, there is no need to rely on visual measurements to confirm the drying point, the drying point can be stably set without relying on human hands, and the drying point can be corrected in real time. Therefore, a resist film with stable sensitivity can be obtained, and final metal thin plate products such as shadow masks and lead frames manufactured therefrom also have high uniformity.

〔Example〕

The basic idea of the present invention is to measure the drying profile of a resist coating film in a continuous drying atmosphere by using a moisture meter that can measure even in a high-temperature atmosphere, and to determine the drying point from this drying profile. The method is to control the temperature, wind speed, wind temperature, etc. of the drying atmosphere so as to determine the drying point and set the drying point at a predetermined position. With this configuration, the dry point can be detected reliably, and a resist film with stable sensitivity can be obtained.

FIG. 1 shows an example of a typical drying profile.

The horizontal axis represents the drying time after the resist coating film enters a continuous drying atmosphere, and the vertical axis represents the moisture content of the resist coating film. The water content decreases rapidly until time T, but stabilizes after time T. This borderline time T is the drying point. By controlling the drying point to a certain position in the drying atmosphere, a resist film with stable sensitivity can be obtained.

By the way, moisture meters based on various principles can be used to measure the moisture content of the resist coating film.
As an example, light at wavelengths absorbed by water and light at wavelengths non-absorbed by water are simultaneously applied to a resist coating film, and the moisture content is determined from the ratio of the intensities of these lights reflected through the film. A moisture meter using the method can be used. Of course, this moisture meter is merely an example, and various known moisture meters can be used.

Now, as shown in the embodiment of FIG. 2, a plurality of such moisture meters are installed from upstream to downstream of the drying atmosphere. That is, the continuous thin metal plate 1 is continuously coated in the coating bath 2.
A resist coating film is formed on one or both surfaces (both surfaces in the example shown in FIG. 2) of the resist film, and the resist is continuously transferred to a drying oven 3 where it is properly and stably dried. In this example, the drying furnace 3 includes seven drying chambers 11 to 11 from upstream to downstream.
17, and each of the chambers 11 to 17 is set to a drying temperature as shown in the figure. ). And each chamber 11~
At 17, there is a moisture meter 2 for measuring the moisture content of the resist coating film.
1 to 27, and a moisture meter 2 is installed at the inlet and outlet of the drying oven 3.
0 and 28 are installed respectively. In the case shown, a moisture meter is also installed on the back side, but it is not shown. FIG. 3 shows the results of actually measuring the moisture content using this arrangement. In FIG. 3, the horizontal axis represents the chamber number corresponding to the drying time shown in FIG. 1, and the vertical axis represents the absorbance of the moisture meter corresponding to the moisture content shown in FIG. 1. The drying point is determined from the intersection of the extrapolated curve connecting the measurement points of the fourth chamber 14, the fifth chamber 15, and the sixth chamber 16, and the extrapolated curve connecting the measurement points of the seventh chamber 17 and the outlet. is estimated. From this graph, it can be seen that the drying point is near the entrance of the seventh chamber 17.

This result was consistent with visual measurements. By determining the drying point as described above, it becomes possible to control the drying line conditions and the drying point.

Next, at an ambient temperature of 80°C, in the same manner as above,
The moisture content of the resist coating film and the actual temperature of the resist coating film were measured, and a drying profile and a substantial temperature curve as shown in FIG. 4 were obtained. By the way, it is known that when the moisture content of a resist coating film exceeds 80%, dripping occurs and the film thickness changes, and when the moisture content falls below 80%, the dripping stops. . Looking at Figure 4 based on this knowledge, the amount of water at which some liquid stops is 80%.
It can be seen that it takes half of the time to reach dryness (in Figure 4, there is a relationship of T2 = 'ATs).
. Therefore, if the fine adjustment of the drying conditions is made in the first half of the total length of the drying oven 3, there is a possibility that the liquid will drip and the film thickness will change.
(between). Note that from the solid temperature curve in FIG. 4, it can be seen that in the early drying stage (up to T), heat is used to raise the solid temperature of the resist coating film, and there is little change in the moisture content. Therefore, in order to increase drying efficiency, it can be said that it is an effective means to raise the temperature of the resist solution as much as possible during coating.

Now, the drying point is determined as shown in Fig. 3, and when there is a change in the drying point, the heating means of the drying oven 3 is manually adjusted.
In particular, it is effective to adjust the heating amount of the heating means in the latter half (the heating means after T2 in FIG. 4), but it is more effective to do this automatically. The configuration for this purpose is shown in FIGS. 5 and 6. Figure 5 is a system configuration diagram,
This control device includes a CPU 4 for inputting moisture content data from the moisture meters 20 to 28 described above, an input device 5 for inputting set values etc. to the CPU 4, and a storage device 6 for storing set values etc. , a heating means control unit 31 that controls the output of each of the heating means 41 to 47, such as far infrared heaters, installed in each of the drying chambers 11 to 17, based on an input signal.
37, and feed back control is performed according to the flow shown in FIG. That is, in step (2), the moisture content of the resist coating film in each of the drying chambers 11 to 17 measured by the moisture meters 20 to 28 is read. Next, in step ■, the third
The position of the drying point in the drying oven 3 is estimated from the intersection of the curves obtained by extrapolation using the method explained in connection with the figure. Next, in step (2), the amount of deviation of the actually estimated position from the preset drying point position is determined. Then,
In step (2), as described above, the output of the heating means in one or more chambers after half of the total length of the drying oven 3 is adjusted in accordance with the amount of deviation determined in step (2). This process is performed continuously. By controlling in this way, there is no need to rely on visual measurements, the drying point can be stably set without relying on human hands, and the drying point can be corrected in real time.

Therefore, a resist film with stable sensitivity can be obtained, and the final products manufactured therefrom, such as shadow masks and lead frames, can also have high uniformity.

In addition, in the above explanation, it was assumed that the drying conditions in the drying oven 3 were set by the ambient temperature.
The present invention is not necessarily limited to this, and the wind speed (air volume), wind temperature, radiation dose, etc. blown onto the resist coating film may be set and controlled.

Next, an example of a drying line in which such drying point feedback control is performed will be shown. The line conditions were as follows.

Line speed: 3.9m/min.

Resist liquid viscosity used: 40° C., 6.8 cps Drying chamber length: 2 m x 7 (see FIG. 2) The drying oven conditions and drying point positions before and after control by the control device in FIGS. 5 and 6 are shown.

As described above, by detecting the drying point from the data from the moisture meter and controlling the temperature etc. of the drying chamber based on this data, the drying point located in the middle of the final chamber 17 (Fig. 2) can be adjusted to the final chamber. 17
I was able to move it to the first half and stabilize it. The final line conditions and drying profile (drying point) are the second
It became as shown in Figure 3.

〔Effect of the invention〕

According to the resist coating film drying method and apparatus of the present invention,
The moisture content of the resist coating film is detected at multiple points in different directions of the metal thin film, and the drying point, which is the point at which drying is completed, is determined from the distribution of the detected moisture content, and the drying point is located at a predetermined position. Since the drying conditions in the drying oven are adjusted accordingly, there is no need to rely on visual measurements to confirm the drying point, the drying point can be stably set without relying on human hands, and the drying point can be corrected in real time. Therefore, a resist film with stable sensitivity can be obtained, and final metal thin plate products such as shadow masks and lead frames manufactured therefrom also have high uniformity.

4. Brief description of the drawings Figure 1 shows an example of a typical drying profile, Figure 2 shows an example of a typical drying profile.
The figure is a diagram for explaining the configuration of an example of a drying oven for carrying out the resist coating film drying method of the present invention, and Figure 3 is a diagram showing the results of actually measuring the moisture content using the arrangement shown in Figure 2. , FIG. 4 is a diagram showing the results of measuring the moisture content of the resist coating film and the actual temperature of the resist coating film, and FIG. 5 is a system configuration I & diagram of the control system of one embodiment of the drying apparatus of the present invention. FIG. 6 is a control flow diagram thereof.

1... Metal thin plate, 2... Coating tank, 3...
Drying oven, 4... CPU, 5... Input device, 6...
Storage device, 11-17... Dryer chamber, 20-2
8... Moisture meter, 31-37... Heating means control unit, 41-47... Heating means Applicant: Dai Nippon Printing Co., Ltd.

Claims (4)

[Claims] (1) A method for drying a resist coating film in the manufacturing process of metal thin plate products in which a pattern is formed on a metal thin plate by chemical etching, in which drying conditions are set in different directions in the direction of movement of a metal thin plate coated with a resist film on at least one side. In a drying method in which the resist coating film is dried by passing it through a drying oven, the moisture content of the resist coating film is detected at a plurality of points in different directions of movement, and the drying point, which is the point at which drying is completed, is determined from the distribution of the detected moisture content. A method for drying a resist coating film, characterized in that the drying conditions in the drying oven are adjusted so that the drying point is located at a predetermined position. (2) The method for drying a resist coating film according to claim 1, wherein the drying conditions are adjusted by adjusting the drying conditions in the latter half of the drying furnace in the direction in which the thin metal plate advances. (3) The method for drying a resist coating film according to claim 1 or 2, wherein the drying conditions are adjusted in real time. (4) In a drying device for a resist coated film in the manufacturing process of a thin metal sheet product in which a pattern is formed on a thin metal plate by chemical etching, a drying oven is used in which a thin metal plate coated with a resist film on at least one side is continuously passed through and dried. A drying oven having a drying condition setting means capable of setting different drying conditions in the direction of travel of the thin metal plate; means for detecting, means for determining the position of a drying point at which drying is completed from the moisture content detected at the plurality of different points, and determining the amount of deviation of the determined drying point position from the set drying point position. 1. A drying apparatus for a resist coating film, comprising: a means for drying a resist coating film; and an adjusting means for changing the output of the drying condition setting means according to the determined amount of deviation.